Evening, My Question Is I Have Been Trying To Concieve

Evening, my question is I have been trying to concieve last 10 months, I am 24 year ols with immunity disorder but never know what's going on with my body. But last 2/3 months my menstrual cycle has changed. I use too have 4 day periods, now last 3 months, periods now are at 2 days worth. Feel pregnant but no positive tests, as well the so called periods still happening.I don't know what to do?